High-temperature superconducting (HTS) tapes, based on YBa2Cu3O7-δ (YBCO), are prepared on textured metallic substrates. The quality of these films with respect to their current-carrying capability, especially in applied magnetic fields, has increased steadily over the years due to a continuous world-wide effort to develop commercial HTS applications. Self-field Ic values of over 700 Amperes (“A”) per centimeter (“cm”) width at 77 K, and conductor lengths of near-kilometer (“km”) length have been achieved. In addition, tape widths are also anticipated to expand to 10 centimeters. For the production of high-quality coated conductors, not only the longitudinal but also the transverse homogeneity in critical current density (“Jc”) is essential. This is especially true with respect to desired striations for AC applications to reduce hysteresis losses. It is also important for assuring a continuing high and uniform current-carrying capability over length for the production of long coated conductors by providing immediate feedback to control production parameters.
The Jc distribution in superconducting thin films can be determined using methods involving magneto-optics, magneto-scan, laser scanning or patterning individual bridges. Many of these methods are either destructive or slow and, therefore, are not suited to monitor tapes for quality control. An apparatus and method for nondestructive, real-time measurement of current distribution in coated conductors remains desirable.